[src/trunk]: src/sys/opencrypto fix reading crp_q without holding crypto_q_mtx

[knakahara <knakahara%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/4f338b253c45
branches:  trunk
changeset: 824435:4f338b253c45
user:      knakahara <knakahara%NetBSD.org@localhost>
date:      Mon Jun 05 09:09:13 2017 +0000

description:
fix reading crp_q without holding crypto_q_mtx

diffstat:

 sys/opencrypto/crypto.c |  7 ++++---
 1 files changed, 4 insertions(+), 3 deletions(-)

diffs (35 lines):

diff -r 5004c8e103ec -r 4f338b253c45 sys/opencrypto/crypto.c
--- a/sys/opencrypto/crypto.c   Mon Jun 05 09:07:46 2017 +0000
+++ b/sys/opencrypto/crypto.c   Mon Jun 05 09:09:13 2017 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: crypto.c,v 1.79 2017/06/05 09:07:46 knakahara Exp $ */
+/*     $NetBSD: crypto.c,v 1.80 2017/06/05 09:09:13 knakahara Exp $ */
 /*     $FreeBSD: src/sys/opencrypto/crypto.c,v 1.4.2.5 2003/02/26 00:14:05 sam Exp $   */
 /*     $OpenBSD: crypto.c,v 1.41 2002/07/17 23:52:38 art Exp $ */
 
@@ -53,7 +53,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: crypto.c,v 1.79 2017/06/05 09:07:46 knakahara Exp $");
+__KERNEL_RCSID(0, "$NetBSD: crypto.c,v 1.80 2017/06/05 09:09:13 knakahara Exp $");
 
 #include <sys/param.h>
 #include <sys/reboot.h>
@@ -939,7 +939,7 @@
 #endif
 
        if ((crp->crp_flags & CRYPTO_F_BATCH) != 0) {
-               int wasempty = TAILQ_EMPTY(&crp_q);
+               int wasempty;
                /*
                 * Caller marked the request as ``ok to delay'';
                 * queue it for the swi thread.  This is desirable
@@ -947,6 +947,7 @@
                 * for batching.
                 */
                mutex_spin_enter(&crypto_q_mtx);
+               wasempty  = TAILQ_EMPTY(&crp_q);
                TAILQ_INSERT_TAIL(&crp_q, crp, crp_next);
                mutex_spin_exit(&crypto_q_mtx);
                if (wasempty)